Spinning of textile yarns



Dec. 1, 1970 BANCROFT ET AL U 3,543,500

SPINNING OF TEXTILE YARNS 3 Sheets-Sheet 1 Filed June 3, 1968 Dec. 1, 1970 H. BANCROFT ET AL, 3,543,500

SPINNING OF TEXTILE YARNS 3 Sheets-Sheet 2 Filed June 5, 1968 Dec. 3, 1970 BANQRQF'T ETAL 3,543,500

SPINNING OF TEXTILE YARNS 3 Sheets-Sheet 3 Filed June 5, 1968 United States Patent 3,543,500 SPINNING 0F TEXTILE YARNS Herbert Bancroft, Queensway, Rochdale, and John M. Shepherd, Edenfield, Ramsbottom, near Bury, England, assignors to T.M.M. (Research) Limited, Oldham, England, a British company Filed June 3, 1968, Ser. No. 734,028 Claims priority, application Great Britain, June 5, 1967, 25,771/67; June 8, 1967, 26,582/67 Int. Cl. D01h 7/74 US. Cl. 5758.89 15 Claims ABSTRACT OF THE DISCLOSURE A method of removing fibres from the fibre-collecting surface of a spinning rotor in an open-end spinning unit, comprising the steps of stopping the feed of fibres to said spinning rotor and applying or maintaining suction to said spinning rotor as it is stopped or at least reduced in speed to cause a reduction in the centrifugal force acting on fibres remaining on said fibre-collecting surface of said rotor, whereby said fibres are withdrawn from said fibrecollecting surface of said rotor and conveyed from said rotor by said suction.

The present invention relates to an open-end textile spinning machine in which discrete fibres are fed in an airstream into a hollow spinning rotor and deposited on an inner surface of the rotor from which they are picked up by a tail end of yarn which is continuously withdrawn from the rotor.

It is known to supply fibres to the spinning rotor from a drafting system or an opening roller by arranging for the fibres from the latter to be delivered in an airstream through a tube to the interior of the hollow spinning rotor where they are collected on an inner surface of the rotor, usually at the maximum internal diameter of the inner surface, and held on the surface by centrifugal force. Fibres are taken off this surface and twisted into a tail end of a yarn in well known manner and the yarn is usually withdrawn from the spinning rotor axially and wound into a package.

The disadvantage of the arrangement hitherto proposed is that if the yarn breaks during spinning it is usual to stop the delivery of fibres to the rotor but because of the delay between the stop motion detecting the broken end and the cessation of the feed, an accumulation of fibres builds up on the fibre collecting surface in the rotor and it is necessary to remove this accumulation of fibres before a tail end of yarn can be pieced up and the spinning operation resumed.

An object of the present invention is to provide an improved method of an apparatus for removing the fibres before piecing up without dismantling the apparatus in the region of the spinning rotor.

According to one aspect of the present invention, there is provided a method of removing fibres from the fibre collecting surface of a spinning rotor comprising the steps of stopping the feed of fibres to the spinning rotor and applying or maintaining suction to the spinning rotor as it is stopped or at least reduced in speed to cause a reduction in the centrifugal force acting on fibres remaining on the fibre collecting surface of the rotor whereby the fibres are withdrawn from the fibre collecting surface of the rotor and conveyed from the rotor by said suction.

According to a second aspect of the present invention there is provided in an open-end spinning unit comprising a spinning rotor, means for driving said spinning rotor and for feeding fibres to said rotor, suction means for applying suction to said rotor, means responsive to an end Patented Dec. 1, 1970 breakage of yarn to stop the feed of fibres to the rotor and control means to stop or reduce the speed of the rotor to cause a reduction in the centrifugal force acting on the fibres held on the fibre collecting surface whereby the fibres are withdrawn from the fibre collecting surface and conveyed from the spinning rotor by the suction of said suction means.

In one embodiment according to the second aspect of the invention, the suction means may comprise a source of suction produced independently of the spinning rotor and applied to said rotor during normal spinning operation and said control means is such as to stop or reduce the speed of the rotor whilst the suction applied to the rotor by said suction means is maintained.

In an alternative embodiment of the invention the rotor itself may produce suction independently of said suction means as a result of its rotation, the control means being such as to apply to said rotor suction from said suction means when the rotor is stopped or its speed reduced.

In a preferred embodiment of the invention the spinning rotor is provided with a spindle extending axially therefrom and rotatably supported in bearings in a spindle support with driving means drivingly engaging the spindle and said control means is such as to cause relative displacement between said driving means and said spindle to disengage the driving means from the spindle.

Some embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

FIG. 1 is a sectional side elevation of an open-end spinning unit according to a first embodiment of the invention,

FIG. 2 is a sectional plan view of part of the unit shown in FIG. 1, taken on the line II-II in FIG. 1,

FIG. 3 is a schematic sectional side elevation of part of an open end spinning unit according to a second embodiment of the invention,

FIG. 4 is a schematic sectional plan view of the apparatus shown in FIG. 3, taken on the line IVIV in FIG. '3,

FIG. 5 is a schematic sectional side elevation of part of an open end spinning unit according to a third embodiment of the invention, and

FIG. 6 is a sectional plan view of the apparatus shown in FIG. 5, taken on the line VI-VI in FIG. 5.

Referring first to FIGS. 1 and 2, a hollow spinning rotor 11 is fixedly mounted on the upper end of a vertically arranged driving spindle 12 rotatably mounted in upper and lower bearings 13, 14 carried in a rotor housing 15 mounted for turning movement about a vertical axis offset from the vertical axis of the spindle 12 in a fixed horizontal support beam 16 which forms part of the machine structure and serves to support a plurality of spinning units at spaced positions along the length of the machine. The support beam 16 is of U-shaped channel section and is mounted on its side so as to provide horizontally extending upper and lower limbs 161, 162, which are bored with registering holes at each spinning station to receive the housing 15.

The rotor housing 15 is formed with a cylindrical shaft portion 151 passing through the registering bores in the support beam 16 and cut away in the region between the two limbs of the support beam 1 6 to reveal the spindle 12 rotatably supported therein, the bearing 13 supporting the top of the spindle 12 being fixedly mounted in the upper part of the shaft portion 151 where the latter passes through the upper limb 161 of the support beam 16, while the bearing 14 supporting the bottom of the spindle 12 is fixedly mounted in the lower part of the shaft portion 151 at a position where it passes through the lower limb 162 of the support beam 16.

The rotor housing at the upper end of the cylindrical shaft portion 151 is formed with a cylindrical enlargement 152 concentric with the shaft portion 151 and formed with a cylindrical recess 153 extending into the enlargement 152 from the upper face thereof in coaxial relation with the spindle 12 and providing a chamber within which the rotor 11 rotates. The rotor 11 is of shallow dished configuration with an upwardly and outwardly extending frusto-conical base portion surmounted by an upwardly and inwardly extending frusto-conical terminal lip portion which leaves the rotor 11 open at the top. The rotor housing 15 is fitted with a cover plate 23 the lower face of which is stepped to form a central cylindrical depending portion 24 which extends downwardly just into the upper open end of the rotor 11, leaving a small annular clearance between it and the terminal lip portion of the rotor 11. The cover plate 23 is formed with a central opening which is fitted with a vertically arranged yarn delivery tube 25 through which the formed yarn 26 from the rotor 11 is continuously passed upwardly and out of the rotor housing 15. The yarn delivery tube 25 extends below the cylindrical depending portion 24 of the cover plate 23.

The cover plate 23 is formed to receive a fibre feed tube 27 which passes through it and terminates at a position close to the fibre collecting surface of the rotor 11. The disposition of the feed tube 27 is such that fibres are delivered by it substantially tangentially to the fibre collecting surface of the rotor 11 and in the present embodiment of the invention the feed tube 27 is cut so that it can be located close to the nip point of a pair of delivery rollers 28, 29 forming part of a high-draft roller-drafting system 30 to which a sliver 31 is fed. The cylindrical enlargement 152 of the rotor housing 15 is provided with two suction ports 33, 34 which extend radially and horizontally through the side wall of the enlargement 152 on axes inclined at right angles to each other and which serve to provide a communication between the recess within which the rotor 11 rotates and a suction pipe 32 opening into a collar 35 fixedly mounted on the upper limb 161 of the support beam 16 and within which the enlargement 152 is rotatably mounted.

The rotor housing 15 is mounted in the support beam 16 by lowering the shaft portion 151 thereof through the bores in the upper and lower limbs 161, 162 until the enlargement 152 on the upper end of the housing 15 bears down on the upper face of the upper limb 161. In this position, the lower end of the shaft portion 151 of the housing projects from the lower face of the lower limb 162 of the support beam 16 and a retaining collar 36 is fitted on the end of the shaft portion 151 so that its upper face bears against the lower face of the lower limb 162. The retaining collar 36 is formed with a radially extending lug 37 through which passes a vertically arranged locating pin 38, the lower end of which carries one end of a tension spring 39 the other end of which is connected to the machine frame While the upper end of the locating pin 38 serves to limit the turning movement of the rotor housing in each direction by its engagement against the longitudinal edge of the lower limb 162 of the support beam 16.

The spinning rotor 11 is arranged to be driven from its spindle 12 by a driving belt 17 which runs along the length of the machine between the two limbs 161, 162 of the support beam 16 and drivingly bears inwardly against the spindle 12 under the action of a jockey pulley 18. In addition, a brake arm 40 in the form of a leaf spring is fixed at one end to the lower limb 162 of the support beam 16 and is provided at its other end with a brake pad 41 which upon appropriate release of the free end of tllae arm 40 resiliently bears inwardly against the spindle For normal running of the spinning unit, the rotor hous- 1ng 15 is turned to a drive-engaging position as shown in full line in the drawings, in which the locating pin 38 on the etaining collar 36 bears against the edge of the lower limb 162 of the support beam 16 and is biased thereto by the tension spring 39, the spindle 12, in its housing 15, then being in engagement with the driving belt 17, the brake arm 40 supporting the brake pad 41 being held by the housing 15 at a. position in which the brake pad 41 is clear of the spindle, and the suction port 33 in the upper end of the housing 15 being in alignment with the suction pipe 32. When it is required to bring the rotor 11 to rest, the housing 15 is turned through by means of a handle (not shown) provided for the purpose, causing the locating pin 38 to move through a position of deadcentre with respect to the tension spring 39 and into its other limiting position against the edge of the lower limb 162 of the support beam 16, the housing taking up a drive-disengaging position, in which the spindle 12 as a result of its eccentric mounting in the housing 15 has moved away from the driving belt 17 and has become disengaged therefrom, the housing 15 has retracted from the brake arm 40 which brings the brake pad 41 thereon into engagement with the spindle 12, and the other suction port 34 in the upper end of the housing 15 has come into alignment with the suction pipe 32.

In operation, cotton sliver is fed to a double apron drafting system from the delivery rollers 28, 29 of which fibres in discrete form are supplied to the feed tube 27 through which they pass into the interior of the spinning rotor 11 and are deposited on an inner collecting surface 21 thereof. The fibres are picked up from the collecting surface 21 to form a twisted yarn 26 which is withdrawn through the coaxially arranged yarn delivery tube 25 from which the yarn is delivered to take-up rollers 42, 43 and from the take-up rollers to a take-up package (not shown). A yarn break detector is provided for detecting a yarn break between the yarn delivery tube 25 and the take-up rollers 42, 43 and includes a yarn feeler arm 44 arranged to bear against the yarn and upon displacement resulting from a yarn break to operate a microswitch 45 controlling the operation of a solenoid-operated air valve which in turn controls the supply of compressed air to a pneumatic ram 47, the piston 48 of which is upon actuation of the ram 47 arranged to bear up against a pivotal plate 49 over which the sliver 31 passes before entering the nip between the back rollers of the apron drafting system 30. When an end breaks, the ram 47 is actuated and the piston 48 extends and raises the plate 49 so as to trap the sliver 31 between the plate 49 and the top back roller and lift the top back roller out of engagement with the bottom back roller, thereby stopping the feed of fibres to the fibre feed tube 27.

It will be appreciated that the yarn break detector operates to stop the feed of fibres to the feed tube 27, but the fibres remaining within the drafting system 30 and the feed tube 27 are delivered to the fibre collecting surface 21 within the rotor 11. In order to remove excess fibres so collected in the rotor 11 rotation of the rotor 11 is stopped and the centrifugal action on the fibres thereby reduced whilst maintaining the suction to the rotor housing 15 so that the latter effectively withdraws the fibres from the rotor. This operation is simply carried out by turning the rotor housing 15 from the drive-engaging position to the drive-disengaging position, in the latter of which the spindle 12 is disengaged from the driving belt 17, the brake pad 41 applied to the spindle and suction to the rotor housing 15 maintained by alignment of suction ports 34 with the suction pipe 32.

The rotor housing may, if desired, be moved to an intermediate position in which neither of the two suction ports 33, 34 communicates with the suction pipe 32, but in which the spindle 12 is removed from the driving belt 17 and the brake pad 41 applied. In this intermediate position the rotor housing 15 is no longer subjected to sub-atmospheric pressure and the cover plate 23 can be removed to give access to the spinning rotor 11 for examination purposes.

In an alternative embodiment of the invention, the rotor 11 may be provided with suction producing means which may take the form of fan blades attached to the rotor and separate suction means provided for applying suction when the rotor is stopped. The separate suction means may comprise the suction pipe 32 for communication with a single port in the rotor housing 15, said port being in communication with atmosphere during spinning and when the rotor housing is turned through 90 as hereinbefore described to stop the rotation is brought into communication with the suction pipe.

A spinning unit according to another embodiment of the invention is ilustrated in FIGS. 3 and 4, in which those parts of the unit which correspond to parts of the unit shown in FIGS. 1 and 2 have been given the same reference numerals. As will be seen, the housing 15 is rotatably mounted in a bracket 16 for rotation about an axis -0 and rotatably supports by means of bearing 13 a spinning rotor 11 which is rotatable about an axis A-A offset from the axis 0-0. The housing .15 is provided with a single port 33 which in the position shown in FIGS. 3 and 4 is in alignment with suction duct 32. The rotor 11 is formed with a downwardly extending hollow spindle 12 having an axial passageway 50 and terminating in an end flange 51. The spindle 12 has fixedly mounted thereon a pulley 52 which in the position shown in the drawings is engaged by a tangential driving belt 17. In the position shown in the drawings, the axial passageway 50 in the rotor spindle 12 is closed at its lowermost end by a flange 53 carried on the upper end of a fixed suction duct 54.

In the operation of the unit shown in FIGS. 3 and 4, fibres are delivered in the form of a sliver by the front rollers 28 and 29 of the drafting system and fed in discrete form through the fibre feed tube 27 to the interior of the spinning rotor 11 which is rotated at high speed by the drive imparted to it by the tangential driving belt 17 which in the drive-engaging position of the housing 15 engages the pulley 52. In the drive-engaging position of the housing 15, the port 33 therein is in alignment with the suction duct 32 thereby creating the required suction in the interior of the housing 15, while the lower end of the axial passageway 50 in the rotor 11 is closed by the flange 53. When it is required to bring the unit to rest, for example, upon an end breakage of yarn, the fibre feed is first cut off and the housing then turned so that the port 33 moves out of alignment with the suction duct 32 thereby cutting off the suction from this source. The rotor spindle 12 moves in an arc to a position in which the fixed pulley 52 thereon is clear of the driving belt and the axial passageway 50 comes into alignment with the suction duct 54, thereby developing an airstream down the passageway 50 which upon reduction in the rotor speed draws with it those fibres remaining in the rotor.

In order that the suction ducts 32 and 54 may be connected to a common source of suction the flange 51 is provided for closing the upper end of the duct 54 at all times except when the passageway 50 is brought into alignment with it.

If the spinning rotor is itself employed to develop the required suction effect within the housing 15 during normal spinning operation and the suction required for removing the residual fibres when the rotor is stopped is provided by the suction duct 54 communicating with the passageway 50, then the flange 51 is omitted so that the suction duct 54 is open to atmosphere except when in communication with the passageway 50.

A spinning unit according to another embodiment of the invention is illustrated in FIGS. and 6, in which those parts of the unit which correspond to those in FIGS. 1 and 2 have been given the same reference numerals. In this embodiment of the invention, the rotor housing is rotatably mounted in a supporting bracket 16 and carries a rotor 11 arranged for rotation therein about the rotary axis of the housing 15. The rotor 11 is driven by the tangential driving belt 17 engaging the pulley 52 on the rotor spindle 12. A pin 55 extends from the lower face of the housing 15 and rotatably supports at its lowermost end a roller 56 and the arrangement is such that by turning the housing 15, the roller 56 can be brought to bear against the belt 17 to move it to the position shown in chain-dot line in FIG. 6 in which it is clear of the spindle pulley 52. At the same time, the pin 55 engages the free-end of a brake arm 57 carrying a brake pad 58, causing the arm 57 to pivot on a pivot pin 59 and bring the pad 58 into engagement with the rotor spindle 12 to stop the rotor 11. This turning movement of the housing 15 also results in the displacement of the port 33, cutting off the interior of the housing 15 from the suction duct 32 and thereby allow the suction applied to the suction duct 54 to withdrawn the excess fibres from the rotor 11 through the axial passageway 50. It may be found advantageous to arrange for the port 33 in the side wall of the housing 15 to be connected either to atmosphere or to a pressurised-air source in the drive-disengaging position as this would allow for the more efficient removal of excess fibres and loose particles from the rotor through the spindle passageway 50 and the suction duct 54.

In some circumstances it may be desirable in the FIGS. 5 and 6 embodiment to provide two ports in the side wall of the housing 15 in such dispositions that suction developed in the suction duct 32 is applied to the housing in the drive-engaging position as well as the drive-disengaging position.

What we claim as our invention and desire to secure by Letters Patent is:

1. In a method of open-end spinning in which fibres in discrete form are fed in an airstream into a hollow spinning rotor and deposited on an internal fibre-collecting surface of the rotor to which they are urged under the influence of centrifugal force and from which they are picked up by a tail-end of a yarn which is continuously withdrawn from the spinning rotor, the steps of stopping the feed of fibres to the spinning rotor and applying suction to the spinning rotor as it is stopped or at least reduced in speed to cause a reduction in the centrifugal force acting on fibres on the fibre-collecting surface of the rotor, whereby the fibres are withdrawn from the fibre-collecting surface of the rotor and conveyed from the rotor by said suction.

2. In a method of open-end spinning in which fibres in discrete form are fed in an airstream into a hollow spinning rotor while suction is applied to said rotor and deposited on an internal fibre-collecting surface of the rotor to which they are urged under the influence of centrifugal force and from which they are picked up by a tail-end of a yarn which is continuously withdrawn from the spinning rotor, the steps of stopping the feed of fibres to the spin ning rotor and maintaining suction to the spinning rotor as it is stopped or at least reduced in speed to cause a reduction in the centrifugal force acting on fibres on the fibre-collecting surface of the rotor, whereby the fibres are withdrawn from the fibre-collecting surface of the rotor and conveyed from the rotor by said suction.

3. An open-end textile spinning unit comprising a spinning rotor having a fibre collecting surface, rotor driving means for driving said spinning rotor, fibre feed means for feeding fibres to said rotor for deposition on the internal fibre collecting surface thereof to which the fibres are urged under the influence of centrifugal force, suction means for applying suction to said rotor, means responsive to an end breakage of yarn to stop the feed of fibres from the fibre feed means to the rotor, and control means to stop or reduce the speed of the rotor to cause a reduction in the centrifugal force acting on the fibres held on the fibre collecting surface, whereby the fibres are withdrawn from the spinning rotor by the suction of said suction means.

4. An open-end textile spinning unit comprising a spinning rotor having a spindle extending axially therefrom rotor driving means, a spindle support rotatably supporting said spindle, a frame rotatably supporting said spindle support for turning movement about a turning axis parallel to but offset from the spindle axis between a drive-engaging position and a drive disengaging position to cause in said drive-engaging position said rotor driving means to be drivingly engaged with said spindle and to cause in said drive-disengaging position said rotor driving means to be drivingly disengaged from said spindle.

5. A unit according to claim 4, wherein said spindle support comprises a housing enclosing the spinning rotor and wherein suction means is provided for applying suction to the interior of the housing in the drive-engaging and drivedisengaging positions of the housing.

6. A unit according to claim wherein the suction means includes a fixed suction duct and wherein the housing is provided with two ports in the side wall thereof, one of which is aligned with the fixed suction duct in the drive-engaging position of the housing to provide a communication between the suction duct and the interior of the housing, and the other of which is aligned with the suction duct in the drive-disengaging position of the housing also to provide a communication between the suction duct and the interior of the housing.

7. A unit according to claim 6, wherein the housing is mounted in said frame for turning movement about said turning axis to a third position to cause the rotor driving means to be drivingly disengaged from the spindle when neither port is aligned with the suction duct.

8. An open-end textile spinning unit comprising a spinning rotor having a spindle extending axially therefrom, rotor driving means, a spindle support which rotatably supports said spindle, a frame rotatably supporting said spindle support for turning movement about the axis of the spindle between a drive-engaging position and a drivedisengaging position to cause, in said drive-engaging position, said rotor driving means to be drivingly engaged with said spindle and to cause, in said drive-disengaging position, said rotor driving means to be drivingly disengaged from said spindle.

9. A unit according to claim 8, wherein said spindle support is provided with a member mounted on said support at a position offset from the turning axis thereof and cooperating with said rotor driving means to cause engagement of said driving means with said spindle when the support is turned to said drive-engaging position and disengagement of said rotor driving means from said spindle when the support is turned to said drive-disengaging position.

10. A unit according to claim 5, wherein the rotor spindle is provided with an axial passageway communicating with said suction duct for the removal of excess fibres from the rotor when the rotor driving means is disengaged from the spindle.

11. A unit according to claim 3, wherein said suction means comprises a source of suction produced independently of the spinning rotor and applied to said rotor during normal spinning operation, and wherein said control means is such as to stop or reduce the speed of the rotor whilst the suction applied to the rotor by said suction means is maintained.

12. A unit according to claim 3 comprising further suction means on said rotor itself and producing as a result of rotation of the rotor a further suction independently of the suction of the first-mentioned suction means, and wherein said control means is such as to apply to said rotor the suction from said first-mentioned suction means when the rotor is stopped or its speed reduced.

13. An open-end textile spinning unit comprising a spinning rotor having a spindle extending axially therefrom, rotor driving means, a control element and a frame rotatably supporting said control element and said spindle for turning movement about the axis of the spindle between a drive-engaging position and a drive-disengaging position to cause, in said drive-engaging position, said rotor driving means to be drivingly engaged with said spindle and to cause, in said drive-disengaging position, said rotor driving means to be drivingly disengaged from said spindle.

14. A unit according to claim 8, wherein the rotor spindle is provided with an axial passageway communicating with a suction duct for the removal of excess fibres from the rotor when the rotor driving means is disengaged from the spindle.

15. A unit according to claim 13, wherein the rotor spindle is provided with an axial passageway communicating with a suction duct for the removal of excess fibres from the rotor when the rotor driving means is disengaged from the spindle.

References Cited UNITED STATES PATENTS 2,926,483 3/1960 Keeler et a1. 5758.95 3,334,479 8/1967 Mikulecky et al. 5758.89 XR 3,334,479 8/1967 Mikulecky et a1. 57--58.89 XR 3,354,626 11/1967 Cizek et a1. 5758.89 XR 3,375,649 4/1968 Bures et a1. 5758.91

STANLEY N. GILREATH, Primary Examiner W. H. SCHROEDER, Assistant Examiner U.S. Cl. X.R. 

